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101.
This paper presents a neural network-based Lyapunov energy function for the weighted least-squares design of IIR all-pass filters. In the proposed method, the error reflecting the difference between the desired phase response and the phase of the designed IIR all-pass filter is formulated as a Lyapunov error criterion. Based on the neural network architecture and suitable Hopfield parameters, the optimal filter coefficients can be obtained when convergence is achieved. Furthermore, a weight updating function is proposed to achieve accurate approximation of the equiripple response. The simulation results indicate that the proposed technique can achieve high performance in a parallel manner.  相似文献   
102.
Testbenches play one of the most important roles in simulation-based design verification. Given a simulation scenario, a testbench provides specific vectors to simulate the design, then collects responses from the design to monitor whether the simulation has satisfied the scenario. The major bottleneck in writing testbenches is generating valid simulation vectors. Many current automatic-vector-generation methods focus on exploring a design's state space. Due to memory or runtime limitations, these methods cannot keep up with the rapid growth of design complexity. We propose a novel algorithm based on the divide-and-conquer paradigm that helps these methods decompose the design's complexity. The algorithm uses a partitioning method that recursively divides a design into smaller, more manageable components. Other approaches handle the divided components while maintaining the entire design's proper functioning. Random simulation generates sets of simulation vectors by randomly assigning the logic values to the design's primary inputs (Pis) one cycle at a time. Unlike random simulation, which uses only a single trace, symbolic solvers attempt to simultaneously enumerate all possible primary inputs to explore the entire state space. They typically use binary decision diagrams (BDDs) or satisfiability (SAT) solvers as their core engine.  相似文献   
103.
A novel two-dimensional electronic beam scanning technique using a linear leaky-wave antenna array with coupled oscillators is introduced, eliminating the need for phase shifters. The measured H-plane main beam can be continuously scanned from 70 to 40° as the frequency varies from 7.9 to 9.05 GHz. By detuning the free running frequencies of the end elements, the measured E-plane main beam can be continuously scanned from -22 to +26  相似文献   
104.
The low-cost and low-electromagnetic-interference (EMI) packaging of optical transceiver modules employing housings of plastic composites are developed and fabricated. Optical transceiver modules fabricated by the plastic composites with transmission rates of 1.25 and 2.5 Gb/s are tested to evaluate the electromagnetic (EM) shielding against emitted radiation from the plastic packaging. The results show that these packaged optical transceiver modules with their high shielding effectiveness (SE) are suitable for use in low-cost and low-EMI Gigabit Ethernet lightwave transmission systems. By comparison of cost, weight, and shielding performance for optical transceiver modules fabricated by the housings of nylon and liquid-crystal polymer with carbon fiber filler composites, woven continuous carbon fiber (WCCF), and nanoscale hollow carbon nanocapulses (HCNCs) epoxy composites, the WCCF composite shows lower cost, lighter weight, and higher EM shielding than the other types of composites. Future studies may develop the low-cost and low-EMI optical transceiver modules using nanoscale HCNCs that have the combination of excellent physical and mechanical properties, light weight, and thinness compared with the conventional fabrication techniques.  相似文献   
105.
The indium-tin oxide (ITO) films with low sheet resistance and conducting transparency have been used on the AlGaInP double-heterostructure orange light-emitting diodes (LED's) to improve the light extraction from the LED surface and device reliability. The orange LED's with ITO films exhibit a light output power of 1 mW at 50 mA, which corresponds to an external quantum efficiency of 1.1%. They can operate stably for more than 3000 h at 20 mA and 25°C without any degradation  相似文献   
106.
Lung disease is a rare complication of inflammatory bowel disease (IBD). Herein is a series of seven IBD patients who developed new, persistent and unexplained symptoms of respiratory disease, particularly chronic productive cough. Using a CT scan of the chest, a diagnosis of bronchiectasis was made in five patients, while the diagnosis of chronic bronchitis was made in two patients. Factors, other than IBD, that could account for pulmonary disease in these patients were absent. Several important clinical patterns for IBD-associated large airway disease were uncovered and are reviewed in light of earlier case reports in the medical literature. A discussion regarding the possible pathogenesis of IBD-associated airway disease follows.  相似文献   
107.
BACKGROUND: Choroidal ruptures occurring as a result of blunt ocular injury are uncommon. A 72-year-old woman sustained blunt trauma to the left eye in 1965. In 1986, she was seen at the Wilmer Institute, and posterior choroidal rupture was documented and fluorescein angiography was performed. Absence of fluorescence was seen in the area of the rupture, and the inferotemporal artery and vein dipped into the area and emerged on the other side of the rupture. METHODS: The eyes were obtained postmortem, and histologic examination was performed. RESULTS: Examination of the left eye revealed a horizontal linear white scar inferior to the optic nerve and macula. Stepped-serial sections through the rupture revealed a 0.7-mm wide defect in Bruch's membrane and retina where fibrous tissue containing melanocytes extended into the vitreous cavity for a short distance. CONCLUSION: The clinicopathologic features of an indirect horizontal choroidal rupture is reported.  相似文献   
108.
Affective instability in borderline personality disorder is due to a marked reactivity to environmental events. The present study focused on the relationship between affective instability and impulsivity in personality disorder. It used an experimental approach in the form of an affect-stimulation design based on the presentation of a short story which allowed for an analysis of affective responses in regard to quality, intensity, and alterations over time. Impulsive personalities showed a strong intensity of affective responses us well as a tendency towards rapid affect alterations supporting the theory of poor affect regulation in subjects with impulsive self-harming behaviour. Results suggest that affective instability is a crucial part of impulsive personality functioning.  相似文献   
109.
An aperture-fed patch antenna array is connected to the open end of a short leaky-wave antenna (LWA) to demonstrate the two-dimensional beam-scanning capability in this paper. This design not only offers another radiation path of the reflected wave, but also creates another scanning radiation pattern on the back plane of the substrate. The reflected wave of the LWA is equally separated by a power divider, modulated by each varactor-tuned phase shifter, and injected into two radiating aperture-coupled antennas. The operated frequencies are tuned to control the LWA main position in the elevation plane; meanwhile, by tuning the phase difference between two phase shifters, the main beam of the aperture-coupled antenna array can be scanned in the backside E plane. Experimental result shows that the suppression of the reflected wave can be 7 dB at 10.0 GHz with a short LWA length of 6 cm (two wavelengths). The H-plane and backside E-plane scanning radiation patterns have great potential in many applications and provide more flexibility to traditional designs.  相似文献   
110.
The objective of this research is to study the degradation of pentachlorophenol with zero-valence iron (Fe(0)) coupled with the use of microwave energy. The sample containing 1000 mg/L PCP solution was dosed with 0.5 g Fe(0) and then subject to 700 W microwave energy for 10s; 85% pentachlorophenol was noted to be removed. If the microwave treatment time was increased to 30s, the pentachlorophenol removal efficiency exceeded 99% with end products including H(2)O, CO(2), HCl, etc. Using Fe(0) as a medium, the microwave treatment is made an efficient method for degrading pentachlorophenol. The time needed to achieve a satisfactory treatment is also reduced leading to significant savings of energy consumption to make this method cost-effective. Since this technology applies Fe(0), which is amenable to natural environment, to speed up the decomposition of an industrial solvent, it is not only cost-effective but also environmental friendly for the industry to pursuit sustainable development.  相似文献   
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